Buy, Sell, Hold: Amazon, Costco, and Walmart Stock Edition

These three retail stocks are known for their low prices, but what do their stocks say about them?U.S. retail is a multitrillion-dollar industry and a pillar of America's economy. Amazon (AMZN -2.33%), Walmart (WMT -0.25%), and Costco Wholesale (COST -0.07%) are industry titans and world-class stocks that have all outperformed the broader stock market over the years.These companies generate an astonishing $1.5 trillion in annual revenue. Their size gives them cost advantages that dominate smaller competitor ...